Background and Objectives: The age at menarche varies from country to country due to regional variation, as well as genetic, environmental and nutritional factors affecting the onset of menarche. This article aims to determine the relationship between the major dietary patterns and the age of menarche in teenage girls in Isfahan, Iran.

Materials and Methods: A descriptive-analytical study was performed. A total of 540 (12-14 years old) schoolgirls in Isfahan were enrolled in this study. Multistage random cluster sampling was performed using Semi-Quantitative Food Frequency Questionnaires, Basic Information Questionnaires, and Anthropometric indices. Odds Ratio (OR) and major dietary patterns were calculated for occurrence of menarche in association with dietary pattern in girls younger than 12 years.

Results: Among the different dietary patterns, three major ones were identified. Weight, BMI, and physical activity were adjusted. The results showed that the girls with higher scores in fatty and junk food dietary patterns compared to other girls with ideal pattern had higher likelihood of younger-than-12 menarche occurrence [(P<0.001, 95%CI: 1.53-4.36, OR=2.48) and (P<0.001, 95%CI: 2.1-4.82, OR=3.2), respectively].

Discussion and Conclusion: In this study, the girls who had fatty and junk food dietary patterns showed higher chance of early menarche. Having a healthy dietary pattern can be associated with normal older-than-12 menarche and decline in early menarche occurrence.

Keywords: Dietary patterns, Age of menarche, Teenage girls